// HTML block

import block_names from '../common/html_blocks.js'
import { HTML_OPEN_CLOSE_TAG_RE } from '../common/html_re.js'

// An array of opening and corresponding closing sequences for html tags,
// last argument defines whether it can terminate a paragraph or not
//
const HTML_SEQUENCES = [
    [/^<(script|pre|style|textarea)(?=(\s|>|$))/i, /<\/(script|pre|style|textarea)>/i, true],
    [/^<!--/, /-->/, true],
    [/^<\?/, /\?>/, true],
    [/^<![A-Z]/, />/, true],
    [/^<!\[CDATA\[/, /\]\]>/, true],
    [new RegExp('^</?(' + block_names.join('|') + ')(?=(\\s|/?>|$))', 'i'), /^$/, true],
    [new RegExp(HTML_OPEN_CLOSE_TAG_RE.source + '\\s*$'), /^$/, false]
]

export default function html_block(state, startLine, endLine, silent) {
    let pos = state.bMarks[startLine] + state.tShift[startLine]
    let max = state.eMarks[startLine]

    // if it's indented more than 3 spaces, it should be a code block
    if (state.sCount[startLine] - state.blkIndent >= 4) {
        return false
    }

    if (!state.md.options.html) {
        return false
    }

    if (state.src.charCodeAt(pos) !== 0x3C/* < */) {
        return false
    }

    let lineText = state.src.slice(pos, max)

    let i = 0
    for (; i < HTML_SEQUENCES.length; i++) {
        // @ts-ignore
        if (HTML_SEQUENCES[i][0].test(lineText)) {
            break
        }
    }
    if (i === HTML_SEQUENCES.length) {
        return false
    }

    if (silent) {
        // true if this sequence can be a terminator, false otherwise
        return HTML_SEQUENCES[i][2]
    }

    let nextLine = startLine + 1

    // If we are here - we detected HTML block.
    // Let's roll down till block end.
    // @ts-ignore
    if (!HTML_SEQUENCES[i][1].test(lineText)) {
        for (; nextLine < endLine; nextLine++) {
            if (state.sCount[nextLine] < state.blkIndent) {
                break
            }

            pos = state.bMarks[nextLine] + state.tShift[nextLine]
            max = state.eMarks[nextLine]
            lineText = state.src.slice(pos, max)

            // @ts-ignore
            if (HTML_SEQUENCES[i][1].test(lineText)) {
                if (lineText.length !== 0) {
                    nextLine++
                }
                break
            }
        }
    }

    state.line = nextLine

    const token = state.push('html_block', '', 0)
    token.map = [startLine, nextLine]
    token.content = state.getLines(startLine, nextLine, state.blkIndent, true)

    return true
}
